How to make objects in a video glow?
You are asking for a tutorial. Instead of giving you the tutorial (this is not a place to demonstrate a whole tutorial) I am going to show you a workflow. Now you can google each of these topics.


Import movie into blender.
Render out as separate images (for convenience).
Place a grey plane in front of the camera.
Shine a spotlight on it where the object you want to glow is.
Insert keyframes and move the light. The light will get animated. Seeing the images from the video in the background helps.
Use the compositor in blender to render out a new movie. The grey plane should be multiplied with the images you rendered out earlier.